From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Performance data table for Bentley Development Cylinder Head H62118.
| Identifier | ExFiles\Box 103\4\ scan0162 | |
| Date | 20th March 1936 guessed | |
| BENTLEY DEVELOPMENT Cylinder Head H62118 R.P.M. | B.H.P. | B.M.E.P. | PTS/BHP/HR. | IGN. ADV. | DETN. PT. 4000 | 101.1 | 89.5 | .603 | 43 | NIL 3750 | 101.8 | 95.8 | .600 | 41 | " 3500 | 100.8 | 101.8 | .567 | 42 | " 3250 | 97.2 | 107 | .561 | 43 | " 3000 | 94.3 | 111.2 | .562 | 39 | " 2750 | 89.3 | 115 | .575 | 40 | " 2500 | 82.8 | 117.2 | .530 | 37 | " 2250 | 76.6 | 120.3 | .520 | 35 | " 2000 | 68.6 | 121.8 | .564 | 31 | + 1750 | 60.3 | 121.8 | .604 | 28 | 1 1500 | 51.4 | 121.0 | .595 | 23 | 5 1250 | 41.8 | 118.5 | .664 | 23 | 18 1000 | 32.8 | 113.6 | .644 | 20 | 24 750 | 23.5 | 110.8 | .640 | 16 | 33 | ||